MEMS Sensor Differential Capacitance Circuit for Precision Detection

The sensor structure is divided into multiple independent beams (first beam, second beam, third beam, fourth beam) that are segmented and arranged symmetrically around the proof mass. Each beam functions as an independent detection element with its own capacitive sensing mechanism. This segmentation allows the sensor to detect signals from multiple directions simultaneously while maintaining structural simplicity through modular design.

The patent employs symmetric arrangement of beams rather than asymmetry. Four beams are positioned at equal intervals (90 degrees) around the proof mass, creating a balanced symmetric structure. This symmetry enables differential measurement that cancels out common-mode noise and improves detection precision while maintaining structural regularity.

The patent combines multiple capacitive sensing mechanisms into a unified detection system. The first and second beams form one capacitive sensing pair, while the third and fourth beams form another pair. These are integrated with differential circuits that process signals from both pairs simultaneously, merging multiple detection functions into a single coordinated system that enhances sensitivity through signal integration.

The differential circuits process capacitor signals from multiple beams and generate feedback signals that are used to drive the proof mass vibration. This feedback mechanism enables active control of the proof mass motion, optimizing the detection signal amplitude and improving sensitivity while maintaining linearity through closed-loop control.

The detection system is segmented into multiple independent beam units (four beams total) that function as separate detection elements. Each beam independently senses capacitive changes, and their signals are processed differentially. This segmentation provides spatial diversity that enables noise rejection through differential measurement, as random noise in individual beams cancels out when combined.

The patent uses symmetric arrangement of four beams positioned at 90-degree intervals around the proof mass. This symmetric configuration enables differential measurement where signals from opposite beams are compared, canceling out common-mode noise while preserving the differential signal that contains the actual measurement information, thereby improving noise suppression.